Hello pit, On 01/20/2011 01:27 PM, pitpom...@arcor.de wrote: > I found a bug in the cpp-wrapper for the ftdi-lib that concerns nearly all > open() functions of the Context-Class. All open-functions except the one with > the usb_device parameter return with -1 (and error string "all fine") even if > opening the device should be posssible (the ftdi-c version can open the same > device). The reason for that behavior is, that they all use for the first > connect to the device the correct ftdi-c-function concerning to the given > parameters (open(vendor,pid) uses ftdi_usb_open(ftdi, vendor, product), > open(description) uses ftdi_usb_open_string(ftdi, description.c_str()) and so > on) but after the first connect they all use the ftdi_usb_get_strings > function that needs as one parameter the usb_device. this has not been set > before when using these special open-functions so it returns with an error > and the open-function failes. > I have already implemented a fix in my sources by adding to further functions > in the ftdi-c-lib that returns by reference the usb_device ande changed the > concerning calls in the cpp-wrapper. That all works fine for me now. > But is a problem in the ftdi-cpp-wrapper worth a change in the ftdi-c-lib? > I will try to commit it if possible today, otherwise next week.
Thanks for the report and your patch! Looking at the C++ wrapper three years later, I don't like the fact that I keeps an own "libusb_device *dev" pointer -and- a pointer to the ftdi_context. I think it can be improved without bloating the open() function of the C API. Something like this: - Remove the libusb_device pointer in the C++ wrapper - Provide a function in the C API to get the strings without closing the device. Thinking about it some more, the C API could do this by default, "wasting" some bytes for an already open device is a non-issue. - Kill the get_strings_and_reopen() function - Implement is_open() in the C API and kill the "open" flag, too. What do you think? Cheers, Thomas -- libftdi - see http://www.intra2net.com/en/developer/libftdi for details. To unsubscribe send a mail to libftdi+unsubscr...@developer.intra2net.com
